CK's Lens Post: Leica Telyt-R 400mm f/6.8, a few images
Rol Lei Nut wrote:
Ching-Kuang Shene wrote:
The Leica Telyt-R 400mm f/6.8 is an odd lens in Leica's lens line-up. It is an achromatic (i.e., 2-element-in-1-group) design, and the only other R lens of this type is Leica R Telyt-S 800mm f/6.3,
There is also a fairly common Telyt-R 560mm.
This one is a newer version with Televit. The Telyt-R 400mm f/6.8 may be earlier and rarer.
This lens is rather unique. It uses push-pull for focusing. The lens front section has a button. One pushes that button to move the front section for focusing. When the subject is in focus, one releases the button to lock the front section in position. This does look like a user-friendly design. However, in some situations such as focusing at a long distance where lens movement is very short, releasing the button could in fact cause the front section to be locked at a location very slightly away from the needed one. Additionally, this lens can be separated into two sections for storage. But, frankly speaking, I never did this.
You can learn to use your palm as a lever, resting it on the lens' body, to make very fine and accurate focus adjustments.
What if it is on a Gimbal? In this case, life is not always that easy. If this push-pull focus is really a good mechanism, many lens manufacturers will follow rather than fixing to rotation. Novoflex follow focus and Leica televit are just two focus mechanisms that never catch the market.
When I was using it often, the ability to take the lens apart for better portability was one of its best features.
To me, I would prefer Tamron Nestar 400mm, because it is cheaper and even more convenient.
Here are some images.
The first is my standard test scene, a bridge 800m away. If you look at the large image, you will see that the center portion is rather sharp. However, the border area does not look good for a Leica lens.
That's a well known limitation and is the very nature of the beast: it was conceived as a wildlife lens, where the subject would be in the center and the image would often be additionally cropped as well (same design philosophy as the Novoflex long teles).
Well, the Konica 800mm f/8 does not suffer from this issue. This is basically a limitation of the achromatic design because two glass elelemnts won't provide a very limited number of tweeking parameters. By the way some Astro Berlin achromatic designs are also good.
With some practice and patience, it can be quite effective, but nowadays I'm more likely to mount a Canon EF 400 5.6 L (+1.4x) on my Sonys if shooting wildlife.
Well, for wildlife I can handle a Nikon 500mm f/4P ED IF better with a monopod. A Questar 700/8 mirror lens or a Rubinar 500/5.6 mirror lens can be more effective if aperture and image quality are not so critical.
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